4 stage cascade

[GuuZ]

@cold_ice

is it possible dat some R507 has leaked away and therefor is causing bad performance?

[Unknown_road]

from the pictures and video it looks like you have pretty much floodback, I recommend you use a TXV for the high stage with a 01 orifice (I think), it will limit the floodback and your still able to give the stage some big loads.

and make sure that every piece of high side of stages 2,3 and 4 is insulated. I now see frozen driers and cappilair, in the drier and cappilair the liquid r1150/r14/r50 warms up and even boils. This isn't very good for performance and gives very inaccurate test results.

Offcourse the suctions also needs to be insulated before you can do some fine tuning but thats logical.

btw are the expansion tanks doing their jobs? normal static pressure?

@guuz, that isn't the problem

[cold_ice]

I will go for a TXV as you suggested. I think an internal equalized will do it. I look if I have a small receiver here, so that I can do this tomorrow.
I will insulate, just wanted to see some ice
Maybe I will go for ethane in the second stage, seems to be the best gas for this job. But it's expensive, so I don't know if I should take the R23 or ethane.
The expansion tanks are working fine, static pressure is ~10bar or below.

[n00b 0f l337]

Definetly try out ethane. Its much easier to condense than ethylene and can actually be easier.

[cold_ice]

Changed the captube for a TEV today. Also added a receiver, sightglass and a new filter.
I only had time to do a short test, but the condensing pressure is alot lower than before. Should work fine.

[charlie]

nice rig.

[Unknown_road]

nice!

[[XC] MarioMaster]

i'd hate to see your power bill - keep it up

[n00b 0f l337]

I wonder if in the end it can be converted to a 5 stage w/ nitrogen..

[Mr. Popo]

Holy Crap!!!
This cascade deserve to have it own song...
"It's colder than ice..."

[godmod]

I wonder if in the end it can be converted to a 5 stage w/ nitrogen..

n2 is liquid at -165°C at 10bar
i think therefor he would have to change all the compressors to bigger ones...
danfoss sc21 is not bad, but for a 5 stager? (i would take a 400V rotary)

btw http://www.airliquide.com/en/busines...r_pressure.gif

wouldnt argon be the better choice for a fifth stage?

[Revv23]

n2 is liquid at -165°C at 10bar
i think therefor he would have to change all the compressors to bigger ones...
danfoss sc21 is not bad, but for a 5 stager? (i would take a 400V rotary)

btw http://www.airliquide.com/en/busines...r_pressure.gif

wouldnt argon be the better choice for a fifth stage?

its only a 4 stage. (lol "only")

anyways, i feel like you should have tried replacing the cap tube before you got a tev, you may have just clogged it.

[cold_ice]

Yes but a TEV should work better. We will see.

[Unknown_road]

its only a 4 stage. (lol "only")

anyways, i feel like you should have tried replacing the cap tube before you got a tev, you may have just clogged it.

I don't think that was the problem, although a cappilair can be used with some load changes I think the load change was to much. So at one point your flooding the compressor and with all the stages powerd up your almost starving the HX.

[cold_ice]

The TEV works very nice! The condensing pressure with load is normal now, 12-13bars. It works alot better than with the captube. Maybe I will get a TEV for the second stage too, for R23.

[Sub zero]

OMG its a monster

-100 club bugger that -150 club i reckon

[Revv23]

I don't think that was the problem, although a cappilair can be used with some load changes I think the load change was to much. So at one point your flooding the compressor and with all the stages powerd up your almost starving the HX.

yeah i agree tev is better to use.

[Extera]

Watching this tread 4 quited a time now, realy awesom to see this monters taking shape.

Can someone tell me what is the lowest temp reached with phase change?

[n00b 0f l337]

-165C ish by pc ice with a 3 stager n methane. Held no load thouhg.

[Extera]

That rocks. To bad it's that pricey to build

[GuuZ]

how are things going with the first 3 stages mr cold_ice ? all 3 stable now?

[cold_ice]

Today I rebuilt the second stage. I use a TEB2 for R23 in second stage, a receiver, a Danfoss sightglass and Castel filter. I hope I get the R23 and the R14 next week, both are ordered.
So gasses will be R507/R23/R14/R50

[cold_ice]

Started with 4th stage yesterday. The R23 should arrive on Thursday, hope the R14 this week too.

[Weee]

All I can say is that considering it's a 4 stage, things look very tidy.

I think we're all anxious to see this one all finished and charged, and it seems like you're getting closer to that goal, keep it up!

[n00b 0f l337]

Will you be adding argon to the r14 for colder temps?